US2422131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined air heater for hot-air turbine and blast furnace
Assignee: Aktiengesellschaft fuer Technische Studien
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Filing: 1944-03-09
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Granted: 1947-06-10
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Expires: 1964-03-09
Abstract
No abstract record available.
Inventors
- 👤 Ruegg Rudolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:21
CPC Classifications
C; C21; C21B; C21B9/00; C21B9/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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GB126940A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-06-09 | 1950-12-09 | 1951-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-06-09 | 1954-12-09 | 1955-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-06-09 | 1958-12-09 | 1959-06-10 | $7700.00 | Window Closed / Lapsed |